US4481119A - Compositions for extinguishing titanium fires - Google Patents
Compositions for extinguishing titanium fires Download PDFInfo
- Publication number
- US4481119A US4481119A US06/474,414 US47441483A US4481119A US 4481119 A US4481119 A US 4481119A US 47441483 A US47441483 A US 47441483A US 4481119 A US4481119 A US 4481119A
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- US
- United States
- Prior art keywords
- titanium
- fire
- extinguishing
- extinguishant
- fluoride
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D1/00—Fire-extinguishing compositions; Use of chemical substances in extinguishing fires
- A62D1/0007—Solid extinguishing substances
- A62D1/0014—Powders; Granules
Definitions
- This invention relates to methods of extinguishing titanium metal fires. More particularly, this invention relates to methods of extinguishing titanium metal fires in a flowing airstream.
- Titanium is a low density, high strength metal which has found increasing utilization in the aerospace industry. Although displaying excellent corrosive (oxidation) resistance at normal temperatures and air pressures, the bulk metal is subject to sustained combustion in pure oxygen and/or pressurized air once sufficient energy for ignition has been obtained.
- One such critical environment for titanium combustion exists in the high pressure compressor sections of gas turbine engines. Titanium has been a material of choice here for weight reduction. However, sufficient energy to cause ignition is obtainable through foreign object damage, blade rubs or strikes, or a blade failure. Once ignited, titanium is actually a very energetic metal and will burn in oxygen and/or nitrogen at a very high temperature (5300° F.) as long as sufficient pressure is maintained. Many conventional extinguishants are not effective and may even be hazardous against titanium fires.
- This invention provides a method of extinguishing a titanium metal fire in a flowing airstream by injecting an extinguishant selected from the group consisting of calcium flouride, lithium fluoride and sodium fluoride into the airstream at a point upstream of the titanium metal fire.
- Thermochemical calculations were conducted (see D. R. Cruise, Theoretical Computations of Equilibrium Compositions, Thermodynamic Properties, and Performance Characteristics of Propellant Systems, Naval Weapons Center Technical Publication 6037, April 1979) to find the anticipated temperature resulting when a titanium fire model of 2/3Ti+1/3TiO 2 and of 1/3Ti+2/3TiO 2 at a typical burning temperature of 3200° K. was treated with a selected weight mass of an extinguishant. As an example, at 50 weight percent extinguishant, half the mass was extinguishant and the other half was the titanium fire model composition.
- the predicted effectiveness of the extinguishants of this invention are shown in Table 1.
- the previously known titanium fire extinguishants of trimethoxyboroxine (TMB) and sodium chloride are included for comparison.
- the resulting computed temperature was desired to be below 1900°-2000° K., the generally accepted value for the ignition temperature of titanium in air.
- the test apparatus for the titanium fires included an air system adapter, an extinguishant delivery system, a test chamber, an ignition system and a control system.
- an air system adapter included an air system adapter, an extinguishant delivery system, a test chamber, an ignition system and a control system.
- a 1/16-inch by 2-inch by 3-inch Ti-6Al-4V alloy specimen was held with the 2-inch dimension vertical and the 3-inch dimension parallel to the airflow.
- Ti-6Al-4V is an alloy commonly used in airplane turbine parts containing 90% titanium, 6% aluminum and 4% vanadium.
- An observation port into the test chamber allowed for the collection of data by high speed movie film (400 frames/second).
- the airflow in the system was obtained by expansion from large pressurized storage tanks.
- the cold air (around 0° F.) was used directly or heated by burning fuel directly in the airstream.
- Depleted oxygen was made up to the original oxygen concentration from a pressurized supply.
- the ignition system was a portable 180 amp DC arc welder to ignite the titanium specimen.
- a powdered solids extinguisher system was used to deliver the extinguishants into the flow stream at a flow rate of approximately 1 lb/sec or 5.8 g/cm 2 -sec.
- the experimental sequence for testing in the titanium fire testing was as follows. Air was adjusted to the desired chamber temperature and static pressure. The camera was started and then the sample was ignited by the electric arc. The airflow was then directed through the test chamber and sustained combustion took place. The extinguishants were then injected upstream of the fire to determine their effectiveness as the material was carried by the airstream to the titanium fire.
- the method of testing the extinguishants involved finding the minimum amount which would put out the titanium fire in 50% or more of the attempts with each extinguishant.
- High speed movie film provided data on ignition, the initial burning rate, and the condition of the titanium fire extinction.
- the extinguishants of Table 1 were all tested to determine the effective amounts needed.
- Calcium fluoride was the most effective extinguishant found. It was effective in the amount of 75 grams to put out the titanium specimen in at least half of the attempts. Both lithium fluoride and sodium fluoride were effective at the amount of 100 grams. By comparison, sodium chloride required 150 grams and the trimethoxyboroxine required 456 grams for 50% effectiveness.
- Calcium fluoride is the most preferred extinguishant for use on titanium fires. It was found the most effective requiring the smallest weight of material. Further, as calcium fluoride has a low solubility in water, the use of calcium fluoride results in a reasonable low toxicity level. Lithium fluoride and sodium fluoride are also effective at combating titanium fires in an airstream.
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Fire-Extinguishing Compositions (AREA)
Abstract
Titanium metal fires are extinguished by the application of a material selected from the group consisting of calcium fluoride, lithium fluoride and sodium fluoride.
Description
1. Field of the Invention
This invention relates to methods of extinguishing titanium metal fires. More particularly, this invention relates to methods of extinguishing titanium metal fires in a flowing airstream.
2. Description of the Prior Art
Titanium is a low density, high strength metal which has found increasing utilization in the aerospace industry. Although displaying excellent corrosive (oxidation) resistance at normal temperatures and air pressures, the bulk metal is subject to sustained combustion in pure oxygen and/or pressurized air once sufficient energy for ignition has been obtained. One such critical environment for titanium combustion exists in the high pressure compressor sections of gas turbine engines. Titanium has been a material of choice here for weight reduction. However, sufficient energy to cause ignition is obtainable through foreign object damage, blade rubs or strikes, or a blade failure. Once ignited, titanium is actually a very energetic metal and will burn in oxygen and/or nitrogen at a very high temperature (5300° F.) as long as sufficient pressure is maintained. Many conventional extinguishants are not effective and may even be hazardous against titanium fires.
Several specific extinguishants have proven useful in combating titanium fires. Examples include the liquid extinguishant trimethoxyboroxine and the solid extinguishants sodium chloride and graphite carbon. However, no specific extinguishant for titanium fires has been designed for use in a pressurized, flowing airstream.
This invention provides a method of extinguishing a titanium metal fire in a flowing airstream by injecting an extinguishant selected from the group consisting of calcium flouride, lithium fluoride and sodium fluoride into the airstream at a point upstream of the titanium metal fire.
It is an object of this invention to provide a method of extinguishing a titanium metal fire. Another object of this invention is a method of extinguishing a titanium metal fire in a flowing airstream. Still another object of this invention is to provide extinguishants effective against a titanium metal fire in a flowing airstream.
Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention.
It has been found that the solid materials calcium fluoride, lithium fluoride and sodium fluoride are all effective in extinguishing titanium metal fires in a flowing airstream.
Thermochemical calculations were conducted (see D. R. Cruise, Theoretical Computations of Equilibrium Compositions, Thermodynamic Properties, and Performance Characteristics of Propellant Systems, Naval Weapons Center Technical Publication 6037, April 1979) to find the anticipated temperature resulting when a titanium fire model of 2/3Ti+1/3TiO2 and of 1/3Ti+2/3TiO2 at a typical burning temperature of 3200° K. was treated with a selected weight mass of an extinguishant. As an example, at 50 weight percent extinguishant, half the mass was extinguishant and the other half was the titanium fire model composition. The predicted effectiveness of the extinguishants of this invention are shown in Table 1. The previously known titanium fire extinguishants of trimethoxyboroxine (TMB) and sodium chloride are included for comparison. The resulting computed temperature was desired to be below 1900°-2000° K., the generally accepted value for the ignition temperature of titanium in air.
TABLE 1 ______________________________________ Titanium Fire Model 2/3 Ti + 1/3 TiO.sub.2 1/3 Ti + 2/3 TiO.sub.2 Extinguishant wt. % ext. Temp. °K. wt. % ext. Temp. °K. ______________________________________ LiF (s) 20 1352 30 1182 CaF.sub.2 (s) 30 954 30 1489 NaF (s) 30 1695 40 1897 TMB (1) 40 1842 40 1424 NaCl (s) 40 1764 50 2003 ______________________________________
To determine the effectiveness of these extinguishants in putting out titanium fires in a flowing airstream such as that found in turbine engines, it was necessary to simulate turbine engine compressor conditions with a test apparatus. The test apparatus for the titanium fires included an air system adapter, an extinguishant delivery system, a test chamber, an ignition system and a control system. Within the test chamber a 1/16-inch by 2-inch by 3-inch Ti-6Al-4V alloy specimen was held with the 2-inch dimension vertical and the 3-inch dimension parallel to the airflow. (Ti-6Al-4V is an alloy commonly used in airplane turbine parts containing 90% titanium, 6% aluminum and 4% vanadium.) An observation port into the test chamber allowed for the collection of data by high speed movie film (400 frames/second). The airflow in the system was obtained by expansion from large pressurized storage tanks. The cold air (around 0° F.) was used directly or heated by burning fuel directly in the airstream. Depleted oxygen was made up to the original oxygen concentration from a pressurized supply. The ignition system was a portable 180 amp DC arc welder to ignite the titanium specimen. A powdered solids extinguisher system was used to deliver the extinguishants into the flow stream at a flow rate of approximately 1 lb/sec or 5.8 g/cm2 -sec.
The experimental sequence for testing in the titanium fire testing was as follows. Air was adjusted to the desired chamber temperature and static pressure. The camera was started and then the sample was ignited by the electric arc. The airflow was then directed through the test chamber and sustained combustion took place. The extinguishants were then injected upstream of the fire to determine their effectiveness as the material was carried by the airstream to the titanium fire.
The method of testing the extinguishants involved finding the minimum amount which would put out the titanium fire in 50% or more of the attempts with each extinguishant. High speed movie film provided data on ignition, the initial burning rate, and the condition of the titanium fire extinction. The extinguishants of Table 1 were all tested to determine the effective amounts needed. Calcium fluoride was the most effective extinguishant found. It was effective in the amount of 75 grams to put out the titanium specimen in at least half of the attempts. Both lithium fluoride and sodium fluoride were effective at the amount of 100 grams. By comparison, sodium chloride required 150 grams and the trimethoxyboroxine required 456 grams for 50% effectiveness.
Calcium fluoride is the most preferred extinguishant for use on titanium fires. It was found the most effective requiring the smallest weight of material. Further, as calcium fluoride has a low solubility in water, the use of calcium fluoride results in a reasonable low toxicity level. Lithium fluoride and sodium fluoride are also effective at combating titanium fires in an airstream.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. In particular, delivery flow rates of extinguishant and the use of certain particle sizes and particle size distributions can be varied to optimize extinguishant performance. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
Claims (3)
1. A method of extinguishing a titanium metal fire in a flowing airstream comprising the step of:
injecting an extinguishant selected from the group consisting of calcium fluoride, lithium fluoride and sodium fluoride into the airstream at a point upstream of said fire.
2. A method of extinguishing a titanium metal fire in a flowing airstream comprising the step of:
injecting an extinguishant of calcium fluoride into the airstream at a point upstream of said fire.
3. A method of extinguishing a titanium metal fire comprising the step of:
applying an extinguishant selected from the group consisting of calcium fluoride, lithium fluoride and sodium fluoride to said fire.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/474,414 US4481119A (en) | 1983-03-11 | 1983-03-11 | Compositions for extinguishing titanium fires |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/474,414 US4481119A (en) | 1983-03-11 | 1983-03-11 | Compositions for extinguishing titanium fires |
Publications (1)
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US4481119A true US4481119A (en) | 1984-11-06 |
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US06/474,414 Expired - Fee Related US4481119A (en) | 1983-03-11 | 1983-03-11 | Compositions for extinguishing titanium fires |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991008799A1 (en) * | 1989-12-19 | 1991-06-27 | The University Of New Mexico | Copper powder fire extinguishant |
US20040094421A1 (en) * | 2002-08-07 | 2004-05-20 | Sams Gary W. | Dual frequency electrostatic coalescence |
US20060273223A1 (en) * | 2005-01-12 | 2006-12-07 | Haaland Peter D | Fire suppression systems |
USRE40651E1 (en) | 1995-04-17 | 2009-03-10 | Eclipse Aviation Corporation | Labile bromine fire suppressants |
CN107693999A (en) * | 2017-09-17 | 2018-02-16 | 江山海维科技有限公司 | A kind of preparation method of high-effect D classes powder extinguishing agent |
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US2787329A (en) * | 1955-01-10 | 1957-04-02 | Callery Chemical Co | Method of extinguishing metal fires |
US3475332A (en) * | 1966-08-12 | 1969-10-28 | Minnesota Mining & Mfg | Fire extinguishing |
US3947365A (en) * | 1972-10-06 | 1976-03-30 | Imperial Chemical Industries Limited | Solid fire-extinguishing compositions |
US3961964A (en) * | 1973-10-24 | 1976-06-08 | The United States Of America As Represented By The Secretary Of The Navy | Coating composition for suppressing combustion of titanium metal |
US3983040A (en) * | 1975-08-07 | 1976-09-28 | Draganov Samuel M | Fire-retardant composition and process of producing same |
US4020903A (en) * | 1968-04-29 | 1977-05-03 | Imperial Chemical Industries Limited | Fire-fighting foam compositions |
US4078953A (en) * | 1975-09-17 | 1978-03-14 | The United States Of America As Represented By The Secretary Of The Army | Reignition suppressants for solid extinguishable propellants for use in controllable motors |
US4149976A (en) * | 1975-11-26 | 1979-04-17 | Commissariat A L'energie Atomique | Powder for extinguishing fires of liquid substances or of a mixture of liquid substances |
US4177152A (en) * | 1976-11-22 | 1979-12-04 | Ceca S.A. | Method of extinguishing metal fires |
US4382884A (en) * | 1980-06-30 | 1983-05-10 | Ciba-Geigy Corporation | Fire-retardant, intumescent composition and its use for the flameproofing of substrates, and as a fire-extinguishing agent comprising an ammonium salt, a water-soluble nitrogen compound as a blowing agent and dextrin |
-
1983
- 1983-03-11 US US06/474,414 patent/US4481119A/en not_active Expired - Fee Related
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US3475332A (en) * | 1966-08-12 | 1969-10-28 | Minnesota Mining & Mfg | Fire extinguishing |
US4020903A (en) * | 1968-04-29 | 1977-05-03 | Imperial Chemical Industries Limited | Fire-fighting foam compositions |
US3947365A (en) * | 1972-10-06 | 1976-03-30 | Imperial Chemical Industries Limited | Solid fire-extinguishing compositions |
US3961964A (en) * | 1973-10-24 | 1976-06-08 | The United States Of America As Represented By The Secretary Of The Navy | Coating composition for suppressing combustion of titanium metal |
US3983040A (en) * | 1975-08-07 | 1976-09-28 | Draganov Samuel M | Fire-retardant composition and process of producing same |
US4078953A (en) * | 1975-09-17 | 1978-03-14 | The United States Of America As Represented By The Secretary Of The Army | Reignition suppressants for solid extinguishable propellants for use in controllable motors |
US4149976A (en) * | 1975-11-26 | 1979-04-17 | Commissariat A L'energie Atomique | Powder for extinguishing fires of liquid substances or of a mixture of liquid substances |
US4177152A (en) * | 1976-11-22 | 1979-12-04 | Ceca S.A. | Method of extinguishing metal fires |
US4382884A (en) * | 1980-06-30 | 1983-05-10 | Ciba-Geigy Corporation | Fire-retardant, intumescent composition and its use for the flameproofing of substrates, and as a fire-extinguishing agent comprising an ammonium salt, a water-soluble nitrogen compound as a blowing agent and dextrin |
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Title |
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Smith, A. J. et al., Comparison Tests for Extinguishing Media on Metal Fires AERE R 6745, Apr. 1971. * |
Stobridge et al., 1979, Titanium Combustion in Turbine Engines, Report Nos. FAA RD 79 51, NBS1R 79 1616, U.S. Department of Transportation, Washington, D.C. * |
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Cited By (30)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5056602A (en) * | 1989-12-19 | 1991-10-15 | University Of New Mexico | Copper powder fire extinguishant |
WO1991008799A1 (en) * | 1989-12-19 | 1991-06-27 | The University Of New Mexico | Copper powder fire extinguishant |
USRE40651E1 (en) | 1995-04-17 | 2009-03-10 | Eclipse Aviation Corporation | Labile bromine fire suppressants |
USRE41557E1 (en) * | 1995-04-17 | 2010-08-24 | Eclipse Aerospace, Inc. | Labile bromine fire suppressants |
USRE41558E1 (en) * | 1995-04-17 | 2010-08-24 | Eclipse Aerospace, Inc. | Labile bromine fire suppressants |
US20040094421A1 (en) * | 2002-08-07 | 2004-05-20 | Sams Gary W. | Dual frequency electrostatic coalescence |
US7886836B2 (en) | 2005-01-12 | 2011-02-15 | Eclipse Aerospace, Inc. | Fire suppression systems |
CN101557858B (en) * | 2005-01-12 | 2013-01-23 | 伊克利普斯宇航有限公司 | Fire suppression systems |
EP1861174A2 (en) * | 2005-01-12 | 2007-12-05 | Eclipse Aviation Corporation | Fire suppression systems |
US7726409B2 (en) | 2005-01-12 | 2010-06-01 | Eclipse Aerospace, Inc. | Fire suppression systems |
US7757776B2 (en) | 2005-01-12 | 2010-07-20 | Eclipse Aerospace, Inc. | Fire suppression systems |
US20070119602A1 (en) * | 2005-01-12 | 2007-05-31 | Eclipse Aviation Corp. | Fire suppression systems |
US20070119603A1 (en) * | 2005-01-12 | 2007-05-31 | Eclipse Aviation Corp. | Fire suppression systems |
EP1861174A4 (en) * | 2005-01-12 | 2010-12-22 | Eclipse Aerospace Inc | Fire suppression systems |
US20060273223A1 (en) * | 2005-01-12 | 2006-12-07 | Haaland Peter D | Fire suppression systems |
AU2006204755B2 (en) * | 2005-01-12 | 2012-01-12 | Eclipse Aerospace, Inc. | Fire suppression systems |
CN102641566A (en) * | 2005-01-12 | 2012-08-22 | 伊克利普斯宇航有限公司 | Fire suppression systems |
US20080115950A1 (en) * | 2005-01-12 | 2008-05-22 | Eclipse Aviation Corporation | Fire suppression systems |
US20140338929A1 (en) * | 2005-01-12 | 2014-11-20 | Eclipse Aerospace, Inc. | Fire Suppression Systems |
CN102641566B (en) * | 2005-01-12 | 2015-05-06 | 伊克利普斯宇航有限公司 | Fire suppression systemsand method |
US9283415B2 (en) | 2005-01-12 | 2016-03-15 | Eclipse Aerospace, Inc. | Fire suppression systems |
US9550081B2 (en) * | 2005-01-12 | 2017-01-24 | Eclipse Aerospace, Inc. | Fire suppression systems |
US20170128758A1 (en) * | 2005-01-12 | 2017-05-11 | Eclipse Aerospace, Inc. | Fire Suppression Systems |
US20230381560A1 (en) * | 2005-01-12 | 2023-11-30 | Aml Global Eclipse Llc | Fire suppression systems |
US10118058B2 (en) * | 2005-01-12 | 2018-11-06 | Eclipse Aerospace, Inc. | Fire suppression systems |
EP3542872A1 (en) * | 2005-01-12 | 2019-09-25 | Eclipse Aerospace, Inc. | Fire suppression system and method |
US20190308042A1 (en) * | 2005-01-12 | 2019-10-10 | Eclipse Aerospace, Inc. | Fire Suppression Systems |
US10881886B2 (en) * | 2005-01-12 | 2021-01-05 | Eclipse Aerospace, Inc. | Fire suppression systems |
US11752375B2 (en) * | 2005-01-12 | 2023-09-12 | Aml Global Eclipse Llc | Fire suppression systems |
CN107693999A (en) * | 2017-09-17 | 2018-02-16 | 江山海维科技有限公司 | A kind of preparation method of high-effect D classes powder extinguishing agent |
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Owner name: UNITED STATES OF AMERICA AS REPRESENTED BY THE SEC Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:RHEIN, ROBERT A.;BALDWIN, JAMES C.;BEACH, CHARLES L.;REEL/FRAME:004107/0100 Effective date: 19830307 |
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